Form for hulls of vessels.



Nrrnn 'STATES PATENT rnicn.

MILLARD FILLMORE MITHOFF, OF NEV ORLEANS, LOUISTANA.

FORM FOR HULLS 0F VESSELS.

SPECIFICATION forming part of Letters Patent No. 630,254, dated August 1, 1899.

Application filed March 2,1899. Serial No. 707,480. (No model.)

To all whom it may con/cern:

Be it known that I, MILLARD FILLMoRn MITHOFF, of New Orleans, in the parish of Orleans and State of Louisiana, have invented a new and Improved Form for the Hulls of Marine Vessels, of which the following is a full, clear, and exact description.

This invention relates to certain improvements in the shaping of the hulls of marine vessels, the object being to so form the hulls that they will be fully adapted to the action of the displaced water in the immediate vicinity of the hull Vwhen the vessel is under way, thus reducing the resistance to the movement of the vessel to a minimum.

This specification is the disclosure of one form of my invention, while the claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure l is a side elevation of the invention. Fig. 2 is a horizontal section through the line 2 2 of Fig. l, which line may also be considered the water-line. Fig. 3 is a vertical cross-section on the line 3 3 of Fig. 1, and Fig. 4 is a similar View on the line 4 4 of Fig. l.

lt is known to me by experiments practically conducted that a solid body moving through water will so throw the water that under the iniiuence of the propelling action of the moving body and the resistance of the surrounding stationary water the water moving away from the body will move in lines each describing parabolic branches. I have further found that as the said body proceeds the displaced water moves back into the wake of the body in currents describing the same kind of curves, except that the curves-are reversed. At the front of said body these currents all move from a central point or focus which is established between the resistant force of the `water and the propelling force of the body and which therefore advances constantly in time with the advance of the body. The same is true of the action at the rear of the body-that is to say, the displaced water all returns in distinct currents which move toward a central point or focus established between the suction of the water at the rear of the body and the propelling force of the body. Applying this theory to a vessel, it follows that from the bow of a boat moving ahead the water in opening moves in lines describing parabolic branches having a common and constantly-advancing focus and that the water displaced closes into the wake at the stern of the vessel in currents describing the reverse of the curves described at the bow, all of the stern-currents having in the same way a common and constantly-advancing focus. Now, therefore, if the hull of a vessel be constructed with its entrance shaped so that the exterior lines of all longitudinal sections at or below the water-line formed on planes all passing through a central horizontal axis will describe parabolic branches the origins of which constitute the cut-Water of the hull and if the run be shaped so that each similar section thereof at or below the waterline describes a reversed parabolic branch the origin of which is at the stern-post of the hull the vessel in moving ahead through the water and in displacing the water in the manner explained above will be fully adapted to the action of the displaced water in moving away from its position of quietude and in returning to the saine. This central longitudinal axis of the vessel referred to above may be considered as coincident with the line d in Fig. 2 and with the point d in Figs. 3 and 4, while the lines e in Figs. 3 and 4 represent planes in which sections if taken will be bounded by the parabolic branches described. Consequently the form of the hull does not interfere with the natural action of the water in its displacement and return, and the result is that the vessel progresses with an entire absence of suction or drag.

The form of the invention shown in the drawings has the hull of the vessel divided into the entrance a, the run ZJ, and a neutral belt or zone c, the purpose of which last is to merge into mechanical regularity the curves of the entrance and run, Fig. 2 being a horizontal section of each side of the hull at the water-line of the vessel and passing, therefore, through the central longitudinal axis at the water-line, (d in Fig. 2 and df in Figs. 3 and 4.) This figure shows the side edges of the entrance a describing parabolic branches the origins of which are at the cut-water or stem of the vessel and the ends of which IOO terminate at the belt c. the run b shaped so that the side edges of the horizontal section *also describe parabolic branche'srever'sedwith respect to those of the entrance and having their origins at the stern-post of the Vessel and their ends merged into 4the belt c. This belt cis not to be identified with the parabolic branches of either the run or the entrance, but is simply a means for merging the ends of the parabolic branches into each other. It should be understood that other sections taken longitudinally on the line d in Fig. 2 and lthe point d in Figs. 3 and 4, but below the Water-line, will show but one side of the hull and not both. All longitudinal sections taken at any point below the Water-line and formed by planes passing through a central horizontal axis-for example, the line d in Fig. 2 and the point d in Figs. 3 and Lt-Will be bounded by parabolic branches; but of course the forms of the parabolic branches will differ according to the cross-sectional model vof the hull. The cross-sectional form of the hull below the Water-line depends on the ratio of beam to depth and must be some segment of a circle, ellipse, or parabola. It may of course have any of these forms consistent with the Fig. 2 also shows' horizontal section that :may be deemed neces sary to the class of vessel constructed.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl. A hul-1 for marine vessels, the hull having an entrance and a run, longitudinal sections of each of which, formed on planes passing through a central longitudinal axis of the hull, are bounded by parabolic branches, the origins of which are respectively at the bow and stern of the hull.

Y 2. A hull for marine vessels, having an entrance and a run, longitudinal sections of each of which, formed by planes passing through a central longitudinal axis of thel hull, are bounded by parabolic branches, the origins of which are respectively at. the bow and stern of the vessel, and the said parabolic branches ending at the greatest beam of the hull, the hul-l havin-g at its greatest beam a neutral zone or belt serving to joinA the ends of the parabolic branches into a mechanically regular form.

MILLARD FILLMORE MITHOFF. Vitnesses:

WM. H. WRIGHT', FRANK SOUL. 

